2.) PS Plus will most likely continue offer current-gen games you still haven't played.
Let's face it, not everyone can afford to buy every single game that's released to the market. Even if I reserve my money only towards the games I want, I am still forced to cut down the list. PlayStation Plus gives me the opportunity to play the games I didn't get the chance to play through their promos.
Even when the PS4 is coming out this month, they managed to release Dragon's Dogma: Dark Arisen for PS Plus owners on the PS3. The next-generation might have a lot of awesome games coming, but I am still not done experience gaming's greats from the current-generation.
Sony will definitely continue to cater to PS3 owners with PS Plus subscriptions especially since we've had a lot of great games released this year and even more to come in this generation.
